A Danish genetic study edited on Cell Metabolism about heart disease has shown that those who possessed one of the two variants of the FGF21 gene, had 20 percent more likely to prefer and look for sugary substances.
In the study, involving 6500 Danish citizens, this gene has provided instructions for the synthesis of a hormone secreted by the liver that controls insulin resistance and sends information directly to the brain.
An area of the brain called nucleus accumbens is considered the epicenter of reward, desire and dependency mechanisms. “It is possible that the desire for sugar and other substances may converge in this region” says David Ludwig, professor at Boston Children’s Hospital, specialized in nutrition and obesity, not involved in the new study.

It is therefore assumed that FGF21, such as leptin, are both hormones that regulate appetite. “We are still investigating why the liver develops this type of mechanism, but we hypothesize that it might be to limit excessive sugar consumption or preventing deleterious effects or promoting diet diversification” says Matthew Gillum, a researcher at the Novo Nordisk Foundation Center for Metabolic Research at the University of Copenhagen and co-author of the study.
In addition, Gillum hopes to undertake further genetic studies about the effect of these variants on body weight and type 2 diabetes, among other issues. “We’ve seen mice without FGF21 consume twice as much sucrose as those who own it,” he says. “We want to study subjects who are completely devoid of FGF21 and answer the question: will they be super greedy for alcohol or sugar?”